Pressure relief valves are widely used in motor vehicles to relieve air pressure surges or peaks in the passenger compartment which result for example, when the doors are slammed shut. The valves generally comprise a simple rigid frame or housing which mounts in an aperture in a vehicle body panel. A valve element in the form of a normally flexible plastic flap is connected to the frame to overlie the aperture in the vehicle body panel. The valve element opens relative to the frame to uncover the aperture to relieve air pressure surges.
The pressure relief valve typically includes latches for securing the valve to the motor vehicle. When installing the pressure relief valve, however, these latches are not visible to assembly line workers. Accordingly, there is no confirmation or feedback that the latches in fact engaged the motor vehicle during installation. There exists a need for pressure relief valves to include visual feedback such that assembly line workers installing the pressure relief valve into a motor vehicle can tell whether or not the latches are fully engaged with the motor vehicle. It is desirable that this feedback does not affect or compromise the ability of the part to seal out contaminants.